Obstetric practices and treatments are steeped in tradition, often introduced without rigorous evaluation based on expert opinion. Practices are often influenced by the media with societal acceptance then entering common practice without an assessment for risk or benefit. Because obstetrics often impacts two patients it is important to understand the potential consequences for both individuals when a new intervention, medication, or device is introduced into clinical practice. A treatment may benefit the mother but harm the fetus or inversely benefit the fetus but harm the mother. These adverse events have both social and financial implications for both the family and society. In addition, new therapeuti interventions can be associated with increased healthcare expenditures. These social and financial burdens need to be determined to help mold health care policy and practice. Since its inception, the Eunice Kennedy Shriver NICHD Maternal-Fetal Medicine Units (MFMU) research network has conducted clinical trials and observational studies that have provided new knowledge to our understanding of pregnancy especially in the area of prematurity. Past studies have demonstrated the benefit of 17-OH progesterone caproate to reduce the risk of preterm delivery and antibiotics to prolonged pregnancy after premature preterm rupture of the membranes. Other studies have demonstrated that new technologies such as fetal pulse oximetry or fetal heart rate ST segment analysis failed to change delivery outcomes. The network studies have played a significant role in providing evidence for and against many practices over the past 24 years. In this application, we demonstrate that the investigators in the Department of Reproductive Biology at Case Western Reserve University (CWRU) have the ability to conduct collaborative research, and have successfully participated in the MFMU research network and therefore qualify to continue on as a study center. Our investigators have a diverse background in clinical trials and multi-centered studies providing a depth of experience for future as well as on-going studies. Our center has performed well in both recruitment and data quality while maintaining high rates of participant retention. The CWRU community (institutional and governmental) has been and continue to be highly supportive of the CWRU-MFMU study center and its investigators. The CWRU study center has provided leadership and participated in the administrative operations that lead to the success of the entire MFMU network. Our use of administrative processes to improve recruitment and hold down costs has been innovative. CWRU provides a strong administrative and research infrastructure such as the CASE-Clinical & Translational Science Collaborative to support our study center operations. The CWRU-Study Center team is ideally positioned to provide leadership with exceptional performance in the coming MFMU Network cycle.